Unit 1

Anatomy

The morphology (structure) of organisms. Can be observed grossly or microscopically

Physiology

The study of life. Specifically how cells, tissues, and organisms function using established principles from physics, chemistry, and biology.

Focus of class

The mechanism of action. How we complete the action.

Homeostasis

Maintaining consistency within the body through negative and positive feedback systems

Negative Feedback

Self-regulating control mechanism that counteracts a change in a system to bring back homeostasis.

Process of Negative Feedback

Set Point → Stimulus Changes Point → Sensed by Receptors → Info sent along affront pathway to control center → info sent along efferent pathway to effector → effector reduces effect of stimulus and brings back homeostasis

Afferent Pathway

Into the brain

Efferent Pathway

Out of the brain

Write an example of a negative feedback process

Done and Right

Positive Feedback Loops

Do not turn off by themselves. Have to have something that shuts it off

Example of Positive Feedback Loop

Done and right

What happens when homeostasis doesn’t work?

Disease

What gives a cell its shape?

Cell membrane

Why is asymmetry within a cell important?

The difference between the external and internal environment is essential for function

Cell membrane

Phospholipid bilayer with polar heads on the outside and non polar tails on the inside

What makes the cell membrane semi-permeable?

The polar heads on the outside and the non polar tails on the inside

What is the cell membrane called in human cells?

A plasma mosaic model

What is scattered within the membrane of a cell?

Integral membrane proteins and peripheral proteins

Integral Proteins

Serve as channels within the cell membrane to regulate intrinsic environment. Connects internal and external environments for selective transport of molecules that can’t otherwise cross the barrier

Intrinsic environment

Internal environment

Extrinsic environment

outside environment

Are peripheral proteins extrinsic or intrinsic?

extrinsic

Peripheral Proteins

Serve many functions. The ones on the outer membrane are involved in self-recognition

Breastfeeding is an example of what and why

Positive feedback loop + It does not turn off by itself

Effector

Opposes initial stimulus until conditions are back to normal for homeostasis

What direction do negative feedback loops produce responses to the stimulus

Opposite direction

What direction do positive feedback loops produce responses to the stimulus

Same direction

What is used within the cell membrane phospholipid bilayer to transport molecules?

Proteins

What are the two categories of transport in regard to energy?

Transport that requires energy from ATP and transport that does not

What does transport that doesn’t rely on ATP for energy use instead?

Molecular energy

What are the three types of diffusion?

Simple diffusion, facilitated diffusion, and osmosis

What is passive movement?

Movement that doesn’t require energy.

Does passive movement have a permeable or impermeable membrane

Permeable membrane

What factors influence simple diffusion?

Magnitude of the driving force, membrane surface area, and permeability of the membrane.

What does the magnitude of driving force refer to in regard to simple diffusion?

How big the concentration difference is between intracellular and intercellular fluid

What does membrane surface area refer to in regards to simple diffusion?

The bigger the cell, the more transfusion can occur

What does the A mean in Fick’s Law?

Membrane surface area. More surface area means more permeability.

What does the P in Fick’s law represent?

Permeability. More holes in the membrane means more diffusion

What does the C mean in Fick’s Law?

Concentration difference across the membrane. A bigger difference means more diffusion

What does the MW in Fick’s law represent?

Molecular weight of the molecule. A higher MW means less diffusion

What does the △X mean in Fick’s Law?

The distance of diffusion. A thicker membrane means less diffusion.

What is facilitated diffusion?

Simple diffusion that needs a little bit of help, usually through the integral membrane. There has to be an open door for molecules to pass through.

Where in the concentration gradient do molecules tend to move from and to?

They move from areas of high concentration to areas of low concentration.

How are poler/ionic molecules different from other molecules?

They use a carrier

What are carriers and channels in regards to facilitated diffusion?

They are like doors

Osmosis

water movement across the membrane.

Is osmosis an active or passive process?

A passive process

What does water follow?

Stuff

Tonicity

Measure of osmotic pressure between 2 solutions separated by a semi permeable membrane. Refers to the solute vs water concentration that pushes water in or out of a cell.

Hypertonic solution

Contains more impermeable solutes than the solution on the other side of the membrane

Hypotonic solution

Smaller concentrations of impermeable solutes than the other side of the membrane

Water moves towards __tonic solution

hyper

Isotonic solution

equal number of solutes as the solution on the other side of the solution

Cells shrink in __tonic solutions and swells in __tonic solutions

hyper, hypo

What type of solution is salt water

Hypertonic solution

Osmoregulation keeps the amount of water the cell loses and gains ___

the same

What are the two main forms of active transport?

Primary active transport and secondary active transport

What does active transport do?

Uses energy to move molecules from low to high concentrations across plasma membranes against the concentration gradient

What type of energy does active transport use?

ATP energy

How does the process of active transport work?

Molecule attaches to transport protein → 3rd phosphate on ATPis cleaved and added to the protein —> Protein changes shape, opening to release the molecule —> 3rd phosphate detaches

Phosphorylation

When ATP loses 3rd phosphate and turns into ADP

Secondary Active Transport

Created by utilizing established concentration gradients. Utilizes ATP energy and energy that was already being used